[PATCH] log: fix crash on empty revision with --copies switch

[Kevin Bullock]

> On Apr 13, 2018, at 23:19, Yuya Nishihara <yuya at tcha.org> wrote:
> 
> # HG changeset patch
> # User Yuya Nishihara <yuya at tcha.org>
> # Date 1523630707 -32400
> #      Fri Apr 13 23:45:07 2018 +0900
> # Node ID 775ad61e04e28c49c78c7936d88826a3df024781
> # Parent  8bacc09814ba5500d15fb40c472e84cb95ae2f99
> log: fix crash on empty revision with --copies switch

Seems like this is appropriate for stable, so unless someone tells me otherwise, I'm going to leave it until after we cut a release candidate (no resend needed).

pacem in terris / мир / शान्ति / ‎‫سَلاَم‬ / 平和
Kevin R. Bullock